This invention relates to liquid level transducers and other sensors associated with tanks, and more particularly to a liquid level transducer having a sealed head construction for use with cryogenic tanks, high pressure containers holding liquefied gas, such as liquefied petroleum gas (LPG), propane, or other fuels that exit the tank in a gaseous state such as nitrogen, oxygen, hydrogen and helium, as well as fuel tanks or other containers for holding a liquid that exits the tank in a liquid and/or gaseous state.
Cryogenic tanks hold the liquefied state of fluids that are normally in the gaseous state at room temperature and atmospheric pressure. Liquefaction of these fluids typically occurs at very low temperatures and/or very high pressures. The measurement of various conditions of these fluids within cryogenic tanks, such as liquid level, temperature, and pressure conditions, are often desired. However, due to the extreme conditions associated with the storage and maintenance of these fluids in the liquefied state, it has been a continuous challenge with the prior art to ensure the integrity of the tank at the measurement point. For example, transducers for measuring the level of liquid in such tanks are typically mounted to the tank wall and extend through an opening in the tank. Leakage of the fluid in the gaseous state can occur if the seal between the transducer and the tank loses its integrity. This problem can also occur internally with pass-thru wires, connectors, and the like, within the transducer, resulting in subsequent loss of the fluid and its attendant cost, health concerns due to exposure, as well as undesirable consequences of the unintended release of volatile or combustible fluids.
It would therefore be advantageous to provide a transducer, mounting head, or the like, that overcomes one or more disadvantages of the prior art.